The present invention relates to an apparatus to refurbish and repair engines, and in particular to an apparatus to remove undesirable deposits located on internal engine parts.
Many modern automotive engines utilize computer controlled fuel injectors to optimize fuel efficiency and minimize emissions. Generally described, the fuel injectors spray a precise and controlled amount of fuel toward an engine intake valve at an optimal time such that the fuel mixes with air and is drawn into the associated engine cylinder in a highly efficient and controlled manner. The timing and amount of fuel sprayed by the injectors is computer controlled to maximize air/fuel mixtures under a variety of operating conditions. Thus, engine performance is optimized to maximize fuel efficiency, power, and startability, while minimizing emissions, engine hesitation and stalling. This precise control becomes particularly important as engines are down-sized and therefore no longer have the reserve of horsepower to overcome minor problems. Further, modern consumers are becoming increasingly sensitive to insufficient horsepower.
About five years ago, a problem was discovered wherein carbon and other materials build up over time on the intake valves of an engine thereby decreasing engine efficiency. There is growing concern over this problem since the problem is particularly prevalent in engines that utilize fuel injectors to spray fuel onto the "backside" of the intake valve. Over time these deposits can become large enough to exhibit a choking effect upon the engine by restricting and disrupting the air flow into the engine cylinders. The amount of build-up can depend upon driving habits and the cleanliness of fuel used, but has been know to reach significant levels even after as little as three thousand miles.
However, performance problems can be experienced even before the deposits become large enough to restrict air flow. The deposits tend to absorb fuels with a sponge-like effect such that the air/fuel mixture is affected. Thus, initial injections of fuel are partially absorbed resulting in an air/fuel mixture that is too lean. Many engines have a fuel enrichment mechanism which operates similar to a choke to add "extra" fuel during initial start-up. The problems of engine hesitation and rough idling are particularly noticeable once the fuel enrichment mechanism is turned off and when the engine is still cold.
Further complicating the overall problem is the difficulty of repair. Typically, the intake manifold of the engine must be disassembled from the cylinder head and the cylinder head disassembled from the engine block so that the intake valves can be individually removed and cleaned. However, this is expensive and time consuming. Further, it is difficult to satisfactorily reassemble engines that have been fully disassembled. For example, it is common for reassembled engines to leak at the gasket between the cylinder head and the engine block, thus necessitating repeated tear-down and rebuild. Thus, complete disassembly often leads to further warranty, repair, and consumer dissatisfaction. As a result, dealerships and/or mechanics will undergo such a major repair only as a last resort, even after proper diagnosis of the problem has been done.
Thus, a tool is desired to remove undesired deposits on an intake valve or other selected internal engine part without requiring complete disassembly of an engine. Further, the tool must facilitate quick and efficient removal of the undesired deposits without undue risk of damage to the engine or risk of safety to the operator using the device.